UFILA Codes

Code for reporting the position, orientation, and magnitude of a filament which has disappeared. A "filament" consists of one or more dark sections which appear to lie along one magnetic inversion line. The properties of only one filament disappearance can be encoded in a single UFILA code.


Example:

Definition of symbols:

  • UFILA comes from disappearing FILAment

  • I I I I I = station indicator

  • UT date of last observation prior to disappearance:
  • Y = last digit of year
  • MM = month of year, 01 = January, 02 = February, etc
  • . DD = UT day of month

  • UT time of last observation prior to disappearance and character of disappearance:
  • HH = UT hour
  • mm = UT minute
  • q = general character of disappearance
    • 1 = slow disappearance, taking more than a half hour
    • 2 = rapid disappearance, taking less than a half hour
    • / = character of disappearance not determined

  • UT date of first observation after disappearance:
  • Y = last digit of year
  • MM = month of year, 01 = January, 02 = February, etc.
  • DD = UT day of month

  • UT time of first observation after disappearance and number of filament segments:
  • HH = UT hour
  • mm = UT minute
  • n = number of filament segments encoded

  • Coordinates (at the time of last observation) of one end of the filament or filament segment:
  • Q = heliographic coordinates of the point (use)
    • 1 = NE (northeast)
    • 2 = SE (southeast)
    • 3 = SW (southwest)
    • 4 = NW (northwest)
    • (use / / / / / if coordinates cannot be determined)
  • XX = distance to central meridian in degrees (longitude)
  • YY = heliographic latitude in degree

Note: Use / / / / / if coordinates cannot be determined. The location and orientation of a filament is described by specifying two or more positions along the filaments. The first position, described above, corresponds to one endpoint. Subsequent positions, described below, refer to points of inflection where the gross orientation of the filament changes markedly. Between two consecutive points, the filament should lie approximately along a great circle arc. The final position refers to the other endpoint.

  • Descriptive data on filament segment:
  • aaa = reduction in the uncorrected area of the envelope containing the dark matter in the
    • 1 = meter-wave noise stormfilament segment (in heliographic square degrees at disk center) replaced by /// if undetermined for any reason
  • e = extent to which the filament segment has disappeared
    • 0 = no disappearance
    • 1 = incomplete disappearance with section of filament segment remaining
    • 2 = faint trace of entire filament segment remains
    • 3 = complete disappearance
    • / = not determined or not relevant
  • d = darkness of filament segment
    • 1 = faint
    • 2 = normal
    • 3 = dark
    • / = not determined or not relevant

Note: The interval between two consecutive positions is called a "filament segment" and its characteristics are described above. The filament need not appear continuous, in the form of dark absorbing material, over the entire segment. Filament material is nearly always irregular in shape and density, which complicates the measurement of its area. Measurement of the area of a segment is made by first constructing an envelope which loosely encloses the dark matter of the filament segment. The area indicated in the code should be the reduction in the area of this envelope between the last time the filament was observed prior to disappearance and the time of the first observation after disappearance.

  • Coordinates of the other end of the filament or filament segment:
  • Q = heliographic coordinates of the point
    • 1 = NE (northeast)
    • 2 = SE (southeast)
    • 3 = SW (southwest)
    • 4 = NW (northwest)
  • XX = distance to central meridian in degrees (longitude)
  • YY = heliographic latitude in degrees

Note: Use / / / / / if coordinates cannot be determined.

If a filament extends from the disk to beyond the limb, then one endpoint will correspond to a disk position and the other endpoint will correspond to a limb position. If the filament lies entirely beyond the limb (prominence), only two positions indicating the limb extent of the prominence should be given. In these cases the area may include measurements made of material both on the disk and above the limb.

  • 99999 = end of message terminator; indicates that entire message has been received

Note: / is to be used for data not available.